Dishwasher self cleaning arrangement



y 1963 H. J. KALDENBERG ETAL 3,090,391

DISHWASHER SELF CLEANING ARRANGEMENT 3 Sheets-Sheet 2 Filed Feb. 2, 1961 d O 0 4 7 l 2 AI 4 3 4, $5 4/ W e A, W I 4, 4 A; 6 I 2 h. L x HM \1 1 7 U s 1 Al Al- 9 a! A- Z A- 1 1 a ,{Jnveniwrs ,dval Gene 'Dulchar 5 Hmn J. Kaldanber lgenl y 1963 H. J. KALDENBERG ETAL 3,090,391

DISHWASHER SELF CLEANING ARRANGEMENT Filed Feb. 2, 1961 3 Sheets-Sheet 3 4e 1! 4' 52 ii 25 I 50 New J Koldanbc z g 23M iganl United rates Patent G 3,090,391 DISHWASHER SELF CLEANING ARRANGEMENT Henry .I. Kaldenberg, Des Moines, and Ival Gene Dutcher, Newton, Iowa, assignors to The Maytag Company, Newton, Iowa, a corporation of Delaware Filed Feb. 2, 1961, Ser. No. 86,607 2 Claims. (Cl. 134104) The present invention is directed to an apparatus for washing dishes, and more particularly, to a dishwasher provided with a self-cleaning filter.

In the usual dishwashers the dishes are placed in a rack which is inserted in the washing compartment. Sprays of water are discharged against the dishes from many different angles supplied under pressure by a pump. The pump recirculates Water from a receptacle or sump located at the bottom of the washing chamber. In recirculating the water, it is conventional to separate the food particles with a strainer. The strainer is positioned in the path of the recirculated washing fluids. After a period of use, the strainer collects a layer of foreign material which impedes the recirculation.

It is, therefore, an object of this invention to provide a device for cleaning the strainer in the recirculation system of a dishwasher. It is a further object of the invention to provide a self-cleaning filter in a dishwasher. Further objects and advantages of this invention will become evident as the description proceeds and from an examination of the accompanying drawing'which illustrates one embodiment of the invention and in which similar numerals refer to similar parts throughout the several views.

In the drawing:

FIGURE 1 is an elevational view partly broken away and partly in section illustrating a dishwasher embodying the present invention;

FIGURE 2 is a view in horizontal section of the dishwasher embodying the invention;

FIGURE 3 is a sectional view substantially taken along line 33 of FIGURE 2;

FIGURE 4 is an enlarged sectional view of the strainer in the dishwasher of the invention; and

FIGURE 5 is a top plan view of the strainer shown in FIGURE 4..

Referring now to the drawing, the reference numeral 16 indicates generally a dishwasher having a supporting frame 11 and cabinet 12. Within the cabinet is a washing chamber 13 having tracks 14 for receiving dish racks containing the articles to be washed.

A fluid discharge device '16 is located at the bottom of the washing chamber 13 for circulating washing fluids against the dishes contained in baskets supported on the tracks 14. The discharge device may be in the form of a rotating arm 17 containing jets 18 for impinging streams of water against the articles supported on the racks. The rotating arm 17 may be journalled on vertical column formed by pipe 19.

At the bottom of the washing chamber 13 is located a receptacle which may be in the form of a sump 20. The sump 29 communicates with the washing chamber 13 through an opening 21.

A pump 22 circulates the washing fluids through the discharge device 16 from the receptacle .20 in which the washing fluids are collected after splashing oif the dishes in the washing chamber. The pump 22 is connected to the receptacle 20 through a conduit 23 which communicates with orifice 25 in the bottom wall of the receptacle. The pump 22 is connected to the discharge device 16 through conduit 24 and vertical pipe 26. A branch conduit 27 is connected to conduit 24 to bleed a small amount of the recirculated washing fluid into the receptacle 20 for the purposes to be described hereinafter.

Positioned in the path of recirculation of the Washing fluids is a strainer 30. The strainer surrounds orifice 25 with a cylindrical screen 31 mounted in a groove 32 formed in the bottom wall of the receptacle. A cover 34 is provided for the top of the cylindrical screen so that the washing fluids are required to traverse the screen 31 prior to entering conduit 23 when recirculated by the pump 22 through the discharge device 16.

A cover 34 is mounted on a shaft 35, the bottom end of said shaft being fixedly received by hub 36 formed in the receptacle. The cover is retained on shaft 35 by a threaded knob so that the strainer may be readily removed, cleaned and inspected.

Positioned within the strainer 30 is a cleaning mechanism in the form of a spray device 40 having a rotatable arm 41 journalled on shaft 35. At the end of the arm 41 is a fan spray head 42 containing jet nozzles 43 for impinging washing fluids against the inner surface, or downstream side, of the screen 31. The jet nozzles 43 at the end of the rotating arm 41 of the spray device 4t) are supplied with washing fluids through the conduit 27 which is connected to conduit 24, as previously explained. The conduit 27 communicates with vertical column 45 containing fluid passages 46 for supplying washing fluids to the spray device 40. Passageways 47 in the spray device supply the jet nozzles 43 with fluids from vertical column 45.

Formed in the bottom of the receptacle 20 is a trough 50 below and surrounding the strainer 30 for collecting the foreign particles dislodged from the external, or upstream side, of the screen by spray device 41). The trough 50 is connected to a drain conduit 52 so that during draining operations the foreign particles are flushed from the trough into the drain conduit to a suitable disposal by a drain pump 54.

A butterfly valve 53 is placed in the vertical pipe 26 and controlled by a solenoid actuated linkage (not shown).

From the foregoing it is believed that operation of the device is apparent. The washing fluids are circulated by pump 22 to the discharge device 16 through the conduit 24 and returned through the conduit 23 communicating with the receptacle at the bottom of the Washing chamber through an orifice 25. Surrounding the orifice is a strainer having a screen 31 which separates foreign particles from the washing fluids before they enter orifice 25. The downstream side of the screen 31 is traversed by rotating spray device 40 which projects jets of water thereon to dislodge the foreign particles collected on the upstream side.

During a washing operation, the foreign particles dislodged from the screen 31 fall in the trough 50 which communicates with, and is connected to, the drain conduit 52. In this way, the dislodged particles are washed away through the trough 50 into the drain conduit 52 during draining operations. Butterfly valve 53 is in the open position during the washing operation thus permitting only a predetermined portion of the total flow from pump 22 to flow to the spray device 40 while the major portion of the flow is to the discharge device 16. However, upon initiation of the drain period, the butterfly valve 93 is closed to direct the entire flow from pump 22 to the spray device 40 to vigorously flush the foreign particles from the screen 31 and assist in flushing the trough 5t). A drain pump 54- is activated during draining operations to remove to a suitable drain the washing fluids and foreign materials from the dishwasher.

In the drawing and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only, and not for purposes of limitation. Changes in form and the proportion of parts, as well as the substitution of equivalents are contemplated, as circumstances may suggest or render expedient, without departing from the spirit or scope of this invention as further defined in the following claims.

We claim:

1. In a dishwasher having a washing period and a draining period, the combination comprising; a washing chamber; a fluid discharge device for introducing washing fluids into said chamber; a receptacle for receiving the washing fluids from said chamber; a pump; a discharge conduit connected from said receptacle to said pump for returning washing fluids from said receptacle to said pump; a supply conduit connected to said pump for supplying washing fluids from said pump to said fluid discharge device; a self-cleaning filter means including a cylindrical strainer mounted on a vertical axis in said receptacle and disposed between said washing chamber and said discharge conduit in the path of the recirculated washing fluids in order to collect foreign particles on the upstream side of said strainer, a shaft member coaxially disposed relative to said cylindrical strainer, a revoluble spray device inside said cylindrical strainer mounted on said shaft member for projecting fluids against the downstream side of said strainer for dislodging the foreign particles thereon, a cover member over the top of said cylindrical strainer mounted on said shaft member and means retaining said cover on said shaft member whereby said strainer is removably retained between said cover and said receptacle; a spray conduit connecting said supply conduit to said spray device and constructed and disposed to supply a predetermined portion of the total fluid flow from said pump to said spray device during said washing and drain periods; trough means formed in said receptacle adjacent the upstream side of said strainer; and a drain conduit connected to said trough for conducting the foreign particles to drain during said draining period.

2. The invention in accordance with claim 1 wherein said supply conduit further contains a diverter valve and means controlling said diverter valve to divert all the fluid from said pump to said spray conduit during said drain period.

References Cited in the file of this patent UNITED STATES PATENTS 1,899,019 Deutsch Feb. 28, 1933 1,955,199 Menge Apr. 17, 1934 2,552,493 Newton May 8, 1951 2,808,842 Pollock et a1. Oct. 8, 1957 2,824,648 Bear Feb. 25, 1958 2,894,631 Levit et al. July 14, 1959 

1. IN A DISHWASHER HAVING A WASHING PERIOD AND A DRAINING PERIOD, THE COMBINATION COMPRISING; A WASHING CHAMBER; A FLUID DISCHARGE DEVICE FOR INTRODUCING WASHING FLUIDS INTO SAID CHAMBER; A RECEPTACLE FOR RECEIVING THE WASHING FLUIDS FROM SAID CHAMBER; A PUMP; A DISCHARGE CONDUIT CONNECTED FROM SAID RECEPTACLE TO SAID PUMP FOR RETURNING WASHING FLUIDS FROM SAID RECEPTACLE TO SAID PUMP; A SUPPLY CONDUIT CONNECTED TO SAID FLUID DISPLYING WASHING FLUIDS FROM SAID PUMP TO SAID FLUID DISCHARGE DEVICE; A SELF-CLEANING FILTER MEANS INCLUDING A CYLINDRICAL STRAINER MOUNTED ON A VERTICAL AXIS IN SAID RECEPTACLE AND DISPOSED BETWEEN SAID WASHING CHAMBER AND SAID DISCHAGE CONDUIT IN THE PATH OF THE RECIRCULATED WASHING FLUIDS IN ORDER TO COLLECT FOREIGN PARTICLES ON THE UPSTREAM SIDE OF SAID STRAINER, A SHAFT MEMBER COAXIALLY DISPOSED RELATIVE TO SAID CYLINDRICAL STRAINER, REVOLUBLE SPRAY DEVICE INSIDE SAID CYLINDRICAL STRAINER MOUNTED ON SAID SHAFT MEMBER FOR PROJECTING FLUIDS AGAINST THE DOWNSTREAM SIDE OF SAID STRAINER FOR DISLODGING THE FOREIGN PARTICLES THEREON, A COVER MEMBER OVER THE TOP OF SAID CYLINDRICAL STRAINER MOUNTED ON SAID SHAFT MEMBER AND MEANS RETAINING SAID COVER ON SAID SHAFT MEMBER WHEREBY SAID STRAINER IS REMOVABLY RETAINED BETWEEN SAID COVER AND SAID RECEPTACLE; A SPRAY CONDUIT CONNECTING SAID SUPPLY CONDUIT TO SAID SPRAY DEVICE AND CONSTRUCTED AND DISPOSED TO SUPPLY A PREDETERMINED PORTION OF THE TOTAL FLUID FLOW FROM SAID PUMP TO SAID SPRAY DEVICE DURING SAID WASHING AND DRAIN PERIOD; TROUGH MEANS FORMED IN SAID RECEPTACLE ADJACNET THE UPSTREAM SIDE OF SAID STRAINER; AND A DRAIN CONDUIT CONNECTED TO SAID TROUGH FOR CONDUCTING THE FOREIGN PARTICLES TO DRAIN DURING SAID DRAINING PERIOD. 